Aim: To follow up a series of patients admitted to a low secure mental health unit for challenging behaviour. Method: Clinical outcome measures (Health of the Nation Outcome Scale (HoNOS), Global Assessment Scale (GAS) and Staff Observed Aggression Scale (SOAS)) and keyworker interviews were used to follow up the progress of patients at least one year after discharge. Results: 33 patients had a mean time since discharge of 43 months. The typical patient was a man with a history of violent offences, admitted from an open ward because of aggression. The observed improvement on HoNOS and GAS during admission had been maintained at follow up. There had been no re-convictions. All patients were compliant with medication. Five patients had been re-admitted to hospital during the follow up period. The current placement showed that more of the patients were in the community compared with at discharge. Conclusion: Patients admitted to a low secure unit improved during their stay and this improvement was maintained at follow up.